An Istanbul court remanded Kavala in custody as part of an investigation into the movement of U.S.-based cleric Fethullah Gulen, which Ankara accuses of carrying out an attempted coup in July last year, the agency said.

It said Kavala was charged with “attempting to overthrow the constitutional order” and “attempting to overthrow the government of the Republic of Turkey”.

Kavala, whose Anadolu Kultur organization is involved in promoting culture and rights, was detained nearly two weeks ago at Istanbul’s Ataturk Airport, prompting expressions of concern from Europe and the United States.

Since the failed putsch on July 15, 2016, more than 50,000 people have been jailed as they face trial and some 150,000 sacked or suspended from jobs in the civil service and private sector.